The art of glass shewing how to make all sorts of glass, crystal and enamel : likewise the making of pearls, precious stones, china and looking-glasses : to which is added, the method of painting on glass and enameling : also how to extract the colours from minerals, metals, herbs and flowers ... : illustrated with proper sculptures / written originally in French, by Mr. H. Blancourt, and now first translated into English ; with an appendix, containing exact instructions for making glass-eyes of all colours.

CHAP. CCII. A Furnace for Painting the Glass, and Setling the Colours.

WE have mentioned this Furnace in Chap. 194. but did not take notice of its Form, or Ap∣purtenances, because the Business which obliges us to speak of it there, is very different from this.

This Furnace must be Square, of good Brick, two Foot high, and so much every way, and have three Divisions; the undermost for the Ashes, must be six Inches high, the middle one for the Fire must be six Inches high, and have its Opening five or six Inches broad, and four deep, with a good Iron-Grate,

[illustration]

and three square Bars of Iron across to sup∣port the Earthen-Stove hereafter described: The uppermost Division must be a Foot high, with a lit∣tle Opening about the middle before of four Inches high, and two wide, to put in and draw out the Ware a Baking, to see if it be well done.

In this uppermost Division must be put the afore∣said Stove of good Fire-proof Crucible Earth, the Bottom an Inch and half thick, and from thence up to the Brim ten Inches full; it must be square as the Furnace, and have two Inches room from on all sides, that the Fire may flame round about it to Bake the Work, and therefore placed exactly in the middle of the Furnace; there must be also in the Fire-part of this Stove, an Opening just against, and of the same Size and Form as that of the Furnace, for the conveniency of putting the Ware in and out.

Take this Method of distinguishing the Furnace in all its parts, and to lay down a clearer description thereof, observe,

The Letter A is the Ash-hole for the Ashes that fall from above through the Iron-Grate; and note, That the wider the Opening is, the more violent will the Fire be.

The Letter B is the Fire-place.

The Letters C are three Square Iron-Bars to sup∣port the Pan for the Ware.

The Letter D is the Opening of the Furnace and Pan, through which the Ware must be conveyed in and out.

The Letter E is the Earthen Pan, wherein all the Painted-Ware must be Baked.

The Letters F are two half Lids of Potters Earth for covering the whole Furnace above: As soon as the Stove is full of Ware, they must be well closed and luted together, to prevent the Air coming in any where but by the four square holes at both ends of the

Lid, and the two Semicircles in the middle, which make a round Hole for a Chimney; when the two half Lids are closed, those five Holes are for letting out the Smoak and Flame of the Furnace.